The Chiefs have connected on a deep ball and a rookie has scored his first touchdown.
Fifth-round pick Cyrus Allen beat A.J. Terrell down the left sideline and Patrick Mahomes hit Allen in stride for a 39-yard TD.
That pushed the Chiefs’ lead to 21-3 with 5:02 left in the third quarter.
Kansas City started its possession with good field position after Atlanta turned it over on downs with an incomplete pass at midfield.
After Mahomes scrambled for a first down on third-and-5, he dropped back and hit Allen for the score.
Mahomes now has three touchdown throws on the day.